I've been trying to achieve this same effect (without this library of course...) I had links pointing to the 'full page' but used jquery to override the click event of the link so that they used ajax to download only a part of the page into a container. Which container, is determined by the javascript, which I carefully write to avoid confusing myself. Which body part to download was determined by the server. I did not have to duplicate my html; The body part was a template by it self, and included by a master template for the full page. When a body part was downloaded, some jquery javascript needed to be re-run. (e.g. $(x).accordion()) Depending on the url, either the full page or just the body part was served.

On incompatible browsers the javascript functionality did not activate and clicking on the links led to the full versions of the page.

Maybe this library can save me some headache.